SummaryTizen will compete with another newcomer, Firefox OS, as well as Microsoft's Windows Phone.

The junior league of smartphone operating systems is getting more competitive. Phones from yet another contender - Tizen - will go on sale this year with a view to eventually competing with the industry leaders, Apple\'s iOS and Google\'s Android.

For now, Tizen will compete with another newcomer, Firefox OS, as well as Microsoft\'s Windows Phone and a revamped BlackBerry operating system.

Most of the impetus behind Tizen comes from cellphone carriers, which want a successful counterweight to the clout of Google and Apple. Samsung has become the world\'s largest maker of smartphones in large part through its embrace of Android.

Tizen has a powerful backer in Samsung Electronics Co. Spokesman Michael Lin confirmed Tuesday that the Korean company is ditching its own, homebrew operating system Bada in favor of Tizen. Samsung will also continue to make Android phones.

Yves Maitre, the executive in charge of handsets at Orange, France Telecom\'s wireless arm, said the carrier expects to launch Tizen phones in France this year and in developing countries next year. He spoke Tuesday to reporters and industry insiders at an event in Barcelona, Spain, on the sidelines of Mobile World Congress, the world\'s largest cellphone trade show.

Sprint Nextel Corp. is a member of the Tizen Association, but it hasn\'t said if it has any plans to bring Tizen handsets to the U.S. Other major backers include Intel Corp. and Huawei Technologies Ltd., China\'s largest phone maker.

Tizen phones will look and work much like Android phones, except that the familiar square app icons are round. By coincidence, that\'s the shape chosen for the Firefox OS, which was revealed in Barcelona on Sunday. Phones from that project are also expected this year.

Both Firefox and Tizen are "open source" projects, managed by non-profit associations. That means the software is freely available to customize, giving phone carriers control over how the software works on the phones they sell. By contrast, Apple maintains complete control over the workings of the iOS software in iPhones.

The idea to create an "open" phone operating system is not new. In fact, Android is an open-source project run by Google. However, one controlled by a non-profit has never been successful. Tizen is based on two failed attempts, MeeGo and LiMo. Frederic Dufal, the technical director of handsets at Orange, said The LiMo Foundation, the most broad-based attempt, was set up in a way that made